ATLANTA — Three states where members of the clergy and justices of the peace today marry gay couples argued on Friday that it’s a violation of states’ rights for the federal government to then “unmarry” those people under the 1996 Defense of Marriage Act (DOMA).

In an amicus brief to a New York case involving a lesbian widow, Vermont, Connecticut, and New York argue that the federal government had no right, despite the federal designation of marriage as being between a man and a woman, to demand $350,000 in estate taxes when Edie Windsor’s partner died. That would not have happened under a marital tax deduction that lets other married couples pass their assets to their spouse without penalty.

The three states who filed amicus briefs argue that states regulate marriage and family relationships and that Congress doesn’t have constitutional authority to interfere with that license at any level.

Several federal and state judges have struck down parts of DOMA, but it was only earlier this year that a federal appeals court in Boston, called it discriminatory regarding partner benefits, saying the law “fails the test” when looking at its “disparate impact on minority interests and federalism concerns.”

The First Circuit panel, however, did not rule on the most controversial aspect of the law, and perhaps its ultimate federalist test: Whether gay marriages are legal, or reciprocal, in states that have laws against the practice.

Meanwhile, the fight between Congress and the Obama administration over how to defend DOMA has added more questions about how far Congress is willing to go to exert its will on the states.

The House Bipartisan Legal Advisory Group (BLAG), led by Speaker John Boehner (R), has taken over defending the law after President Obama said his administration would not – a refusal that DOMA defenders have written is an “unprecedented deviation from the historical norm.” At the same time, 145 House Democrats have signed an amicus brief in support of Ms. Windsor, the New York widow.

So is the constitutional rationale for DOMA fading? Many Americans clearly don’t think so. But even those who wrote the law say a major problem is how the law, in practice, weighs the powers of the federal government against the rights of the states.

The author of DOMA, former Rep. Bob Barr of Georgia, repudiated the law in 2009, saying that federalism provisions that he and his Republican colleagues put into the law to keep it from being used as a cudgel have largely failed.

The problem, he wrote in the Washington Post, is that it created “one-way federalism” since DOMA “protects only those states that don’t want to accept a same-sex marriage granted by another state.”

The National Conference of State Legislatures says 38 states have passed legislation barring same-sex marriages while six states, including the three involved in the New York case, currently allow such unions. Washington and Maryland also passed gay marriage laws, but they have not yet taken effect.

As arguments in the Second Circuit Court are expected to begin Sept. 27, pressure is rising on the US Supreme Court to settle the issue.